Universal Studios had backed itself into a corner. It had committed to a solid release date in the summer of 1985. When Robert Zemeckis dismissed Eric Stoltz, he put the production in jeopardy of missing its target release date. As a result, everything had to be put into overdrive. If the film missed its release window, Universal would have
been in violation of several marketing agreements and the bad publicity could have sunk the film's box office prospects. As a result, the film was the first to take just ten weeks from the end of filming to being released into theaters.
When Universal greenlit the Back to the Future sequels, it originally wanted to make just one. And it wanted that one sequel to be open-ended. Robert Zemeckis, however, wanted a trilogy. He feared that if he committed to just one film, he wouldn't be permitted to finish the trilogy if that film didn't succeed. Even worse, he might watch part III get farmed out to someone else. That's why he decided to try something that had never been done before- produce two films back to back. It would not only save money, but it would ensure that he got to complete his trilogy the way he wanted it.
